Camp exam problem 7

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*Mahi*
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Camp exam problem 7

Unread post by *Mahi* » Fri Nov 04, 2011 11:36 pm

Let $a_1;a_2;\cdots;a_n;b_1;b_2;\cdots;b_n$ be positive numbers. Prove that at least one of the following must be true,
\[\frac{a_1}{b_1} + \frac{a_2}{b_2} + \cdots + \frac{a_n}{b_n} \geq n\]
\[\frac{b_1}{a_1} + \frac{b_2}{a_2} + \cdots + \frac{b_n}{a_n} \geq n\]
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nafistiham
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Re: Camp exam problem 7

Unread post by nafistiham » Sat Nov 05, 2011 12:55 am

again, simple AM-GM
\[\sum_{k=0}^{n-1}e^{\frac{2 \pi i k}{n}}=0\]
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Tahmid Hasan
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Re: Camp exam problem 7

Unread post by Tahmid Hasan » Sat Nov 05, 2011 9:14 am

i did it with AM-HM.:)
বড় ভালবাসি তোমায়,মা

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sm.joty
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Re: Camp exam problem 7

Unread post by sm.joty » Sat Nov 05, 2011 11:03 am

Please post the solution because I can't solve it. :( :(
হার জিত চিরদিন থাকবেই
তবুও এগিয়ে যেতে হবে.........
বাধা-বিঘ্ন না পেরিয়ে
বড় হয়েছে কে কবে.........

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